(function(doc, win) {
            var html = doc.getElementsByTagName("html")[0],
            // orientationchange->手机屏幕转屏事件
            // resize->页面大小改变事件(一边pc端有用)
                reEvt = "orientationchange" in win ? "orientationchange" : "resize",
                reFontSize = function() {
                    var clientW = doc.documentElement.clientWidth || doc.body.clientWidth;
                    if(!clientW) {
                        return;
                    }
                    html.style.fontSize = 52.0833 * (clientW / 375) + "px";
            }
            win.addEventListener(reEvt, reFontSize);
            // DOMContentLoaded->dom加载完就执行,onload要dom/css/js都加载完才执行
            doc.addEventListener("DOMContentLoaded", reFontSize);
        })(document, window);